By Julius (Jay) Wachtel. Hang on to those joints! Last November voters in Washington and Colorado legalized the recreational use of marijuana for those over 21. And while Federal law continues to classify pot as a Schedule I drug (meaning no accepted therapeutic use), Attorney General Eric Holder, who long ago conceded the fight against medical marijuana, seems in no hurry to challenge states who cross what seems like the final line. During an April Congressional hearing he would only say that DOJ’s decision, when made, would place the needs of children first: “When it comes to these marijuana initiatives, I think among the kinds of things we will have to consider is the impact on children,” he said.

Holder’s approach undoubtedly reflects the views of his boss. Shortly after Washington and Colorado made their move, President Obama told Barbara Walters that “it would not make sense for us to see a top priority as going after recreational users in states that have determined that it's legal.” Even so, as a Harvard-trained lawyer, our reluctant leader had to concede that sooner or later the conflict between Federal and State laws would have to be resolved. “I head up the executive branch; we’re supposed to be carrying out laws. And so what we're going to need to have is a conversation about, how do you reconcile a federal law that still says marijuana is a federal offense and state laws that say that it’s legal?”

Of course, it’s more than just the law. Common sense indicates that legalizing marijuana would increase its use, including by youth. If the Attorney General’s decision will hinge on what’s best for kids, the Federal Government’s leading authority on the topic, the National Institute of Drug Abuse, offers some sobering thoughts:

A recent study of marijuana users who began using in adolescence revealed a profound deficit in connections between brain areas responsible for learning and memory. And a large prospective study...showed that people who began smoking marijuana heavily in their teens lost as much as 8 points in IQ between age 13 and age 38; importantly, the lost cognitive abilities were not restored in those who quit smoking marijuana as adults.

Increases in marijuana use have led health authorities to raise a red flag. In a recent review of the health implications of legalization, researchers warned that brain scans of persons who regularly smoked pot before age 16 have shown evidence of reduced function in an area associated with impulsiveness: “The frontal cortex is the last part of the brain to come online,” said Dr. Staci Gruber, “and the most important. Early exposure perhaps changes the trajectory of brain development, such that ability to perform complex executive function tasks is compromised.”

Marijuana use raises serious health and safety concerns. In 2011 Harvard Health reported that pot use during adolescence is associated with an increased risk of serious mental disorders in early adulthood. In a recent study that tracked 2,000 American teens, scientists found that those who regularly smoked marijuana were twice as likely to develop psychosis or schizophrenia. Pot’s strength has also increased over time. According to NIDA’s potency monitoring program, the mean content of THC, marijuana’s psychoactive ingredient, has gone up more than twofold, from 3.4% in 1993 to 8.8% in 2008. Many fear the consequences of unleashing this “new, improved” chemical on the public. Do we really need more learning-disabled teens? More addled drivers on the road? More smoking of any kind?

Until now legal and practical constraints have limited pot’s popularity. But with two states jumping on the legalization bandwagon, it seems only a matter of time before citizens everywhere start clamoring for the right to toke. Meanwhile a host of conflicting laws and policies leave State and Federal authorities unsure how to respond. Should DEA raid marijuana farms? Shut down retail outlets? Can local authorities help? Should they?

What the country needs most is leadership. If the President feels that smoking weed is no more consequential than having a drink, he needs to say so, and to submit legislation that would remove marijuana from Schedule I. If not, he needs to say that, too.